Primary endpoint will be the need of MV within the first 72 hrs of life (excluding the transient tracheal intubation for surfactant replacement: e.g. INSURE). Population size: hypothesizing that SLI maneuver might decrease the need of MV during the first 72 hours of life from 35 to 20% the investigators calculated that 138 newborns must be enrolled in each groups to detect this difference statistically significant with 80% power at 0.05 level.